Help slide - lightbox or layer?

Hi everybody!

I have created a course with a help slide that I have lightboxed.  The issue I am running into is when a person exits and revisits the course.  The client wants the prompt when revisiting, but upon restarting the course, the slide users see is the "Are you sure you want to exit?"  Does anyone know of a way that this lightbox can close upon revisiting, or am I stuck having to place a Help layer on every slide?

Thanks in advance for any ideas!

Jill